Centrifuge nozzle holders



Jan. 29, 1963 H. c. FITZSIMMONS CENTRIFUGE NOZZLE HOLDERS Filed May 7, 1959 INVENTOR HAROLD o. FITZSIMMONS av! a 5 v ATTORNEY United States Patent C) 3,675,696 CENTRIFUGE NOZZLE HOLDERS Harold C. Fitzsimrnons, West Chester, Pa., assignor to The Sharples Corporation, a corporation of Delaware Filed May 7, 1959, Ser. No. 811,682 4 Claims. (Cl. 233-47) This invention pertains generally to centrifuges, and particularly to a type of centrifuge having nozzles positioned about its periphery for the discharge of material from the centrifuge rotor.

Centrifuges having rotors adapted for peripheral discharge through nozzles are well known in the art. The nozzles usually take the form of bushings of extremely hard material, such as tungsten carbide, the bushing having a central discharge channel of relatively uniform and relatively small diameter, e.g. between .035" to .080". The nozzle bushing is held by a nozzle holder positioned in an aperture extending through the peripheral wall of the rotor, the nozzle holder having an interior passageway connecting the interior of the rotor with the channel in the nozzle bushing.

In view of the relatively high stresses to which the nozzle holder and the adjoining supporting structure of the rotor are subjected during use, which typically involves pressures of upwards of 1200 pounds per square inch, the design of the nozzle holder and its supporting structure is accompanied by stringent limitations which heretofore have led to constructions having serious practical shortcomings. Quite apart from the problem of providing a design capable of withstanding extremely high stresses, there are the problems of prevention of leakage under high pressures, of prevention of plugging due to the accumulation under high pressure of solids, such as sludge, and of affording easy and speedy removal for cleaning purposes, either of the nozzle or of the interior of the rotor, or both, without interference from accumulated and hardened solids, about or in between the parts, such as in crevices or cracks, or on shoulders, threads and the like. Also a nozzle holder must be removed on occasion for the replacement of its nozzle bushing which wears fairly rapidly in use, particularly when solids of an abrasive nature, e.g. in the form of sludge, are discharged therethrough.

The foregoing and other limitations on the practicable design of nozzle holders, accompanied by experience in use, has heretofore dictated, in very large part, the insertion of the nozzle holder in theperipheral aperture from the inside of the rotor, a shoulder on the inner end of the nozzle holder usually being employed to prevent the nozzle holder from escaping through the aperture. To change a nozzle bushing in such instances requires the disassembly and reassembly of the rotor, which is a timeconsuming task. Clogging of the nozzle or of the rotor, in such cases, necessitates the same procedure.

There has been a long-felt need for a practicable nozzle holder and rotor structural combination meeting the above-mentioned requirements, as well as afiording the advantages of simplicity and superiority in construction and operation. Such structural combination should provide for rapid removal and replacement of the nozzle holder by inclusion in said combination of means for moving the nozzle holder in and out of its aperture, and for locking it in operative position. It also should provide for insertion and removal of the nozzle holder from the exterior of the rotor to avoid the time-consuming and laborious task of disassembly and reassembly of the rotor for nozzle servicing and nozzle and/ or rotor cleaning purposes.

rotor and nozzle holder construction and combination lows.

3,075,696 Patented Jan. 29, 196? ice capable of withstanding extremely high centrifugal stresses without leakage, and without undue accumulation of. sticky or hardened solids or sticky liquid ori surfaces of movable parts, the nozzle holder being readily and easily inserted and removed from the exterior of the rotor under a positive moving or propelling force, and securely locked in position when inserted in place in the rotor aperture.

Further features of the invention will become apparent to persons skilled in the art from the following particular description made in connection with the drawings in which:

FIGURE 1 is a sectional elevation shown broken through the periphery of a centrifuge rotor;

FIGURE 2 is a section shown broken taken on the line 2-2 of FIGURE 1;

FIGURE 3 is an exploded view in perspective of a form of the invention; and

FIGURE 4 is a view similar to FIGURE 2 illustrating another form of the invention.

Referring now more particularly to the drawings, 10 is a centrifuge rotor having a shell 11 shown reinforced by a circumferential band 12. Shell 11 also is shown provided with a top 13 secured to shell 11 by means of an annular nut 14. Within shell 11 is shown a conventional disc stack 15.

Aperture 16, of which there may be any desired number spaced circumferentially, e.g. 6 to 12, passes through shell 11 and band 12 more or less radially as shown. Aperture 16 is shown provided with a nozzle holder 17.

Nozzle holder 17 is comprised of a body portion 21 having an interior passageway 22 communicating with the interior of the rotor 10, and with outlet aperture 23 in body portion 21. Aperture 23 is shown provided with nozzle bushing 24 having an interior discharge channel 25.

Body portion 21 is provided on a side thereof with an orienting lateral projection 26 having a shoulder 27 at its outer end. Body portion 21 also is provided, at its own outer end, with shoulder 28 spaced from shoulder 27, and between shoulders 27 and 28 with a concave portion 29, preferably of arcuate cross section. The radius of concave portion 29 is conveniently the same as, or slightly larger than, the radius of threaded cylinder 3-1.

Inner end 32 of body portion 21 is provided with a circumferential groove 33, shown with an 0 ring or circular gasket 34, it being noted that orienting projection 26 also is spaced from the inner end of body portion 21.

Adjoining aperture 16 in the peripheral wall of rotor 10, and positioned generally parallel to aperture. 16, is aperture 35. Apertures 16 and 35 are conveniently cylindrical in shape and have center lines sufficiently close to provide a longitudinal opening 36 therebetween. Apertures 16 and 35, for purposes of preserving structural strength in rotor 10, preferably have'center lines falling in the same plane, said plane being at right angles to the ery as indicated at 37.

Cylindrical member 31 is conveniently provided with a recess 38, shown as having a hexagonal cross section, for engagement by a wrench. V

Insertion of nozzle holder 17 in aperture 16'is as fol- 0 ring 34 is placed in groove 33, if not already in this position. Inner end 32 of nozzle holder 17 is inserted in aperture 16 from the outside of rotor 10. Orienting projection 26 enters aperture 37 as nozzle holder 17 slides inwardly, aperture 37 being in reality a lateral extension of opening 16 serving as a guide in orienting nozzle holder 17. Cylindrical member 31 is placed between shoulders 27 and 28, if not already rotatably held in that position, and when the inner end of member 31 reaches aperture 37 it is rotated in a manner to engage on its outer threaded surface 41 threads 37 on the inner surface of aperture35. The rest of the inner movement of nozzle holder 17 is acc'om'plished by the rotation of member 31. Shoulder 42 on the inner end of projection 26 eventually engages shoulder 43 at the inner end of aperture 37, whereupon cylindrical member 31 is tightened to securely hold nozzle holder 17 in oriented position in aperture 16. In such oriented position channel 25 in nozzle bushing 24 occupies a desired oriented position with respect to rotor 10. Typi- Cally, channel'25 is directed backwardly from the direction of rotationof rotor 10, and frequently lightly outwardly as illustrated, a groove 44 in the outer surface of rotor 10 being provided, in the embodiment of FIGURE 2, to permit the escape of effiuent through channel 25, sincein this embodiment the outer end'45 of nozzle holder 17 is flush, or substantially flush, with the outer surface of rotor .10. Bushing 24 and channel 25 may, of course, occupy any other desired position.

When shoulder 42 abuts shoulder 43 and member 31 has" been tightened, inner end 32 of nozzle holder 17 is conveniently flush with the inner periphery of rotor 10 as illustrated, to avoid accumulation of solids about the entrance to channel or passageway 22. ring 34, being positioned in groove 33 adjacent the inner end of nozzle holder 17, prevents leakage past groove 33 onto the movable parts, centrifugal force on ring 34 assisting in assuring a tight seal. I

It is preferred to produce the various parts of nozzle holders un'th small tolerances as to fit. Under the circumstances it is not uncommon for nozzle holders to stick in their apertures, particularly when sticky or other substances have somehow gotten on the parts, and thus resist removal to the extent of presenting, in some instances, a real problem. This is particularly true when the outer surface of the nozzle holder is a smooth surface, and is made flush, or substantially flush, with the outer periphery of'the rotor, a construction which is highly preferred in many instances, but aitords no opportunity to engage the end of an inserted nozzle holder, such as with a tool. Also, at'times, insertion of the nozzle holder from the exterior ofthe rotor may present ditficulties.

An outstanding feature of the invention is the provision ofmeans for positively moving or propelling the nozzle holderin and out of position in a rotor periphery. In the embodiments illustrated, such positive movement of the nozzle holder is afiorded by the rotation of member 31. Thusto remove the nozzle holder 17 from rotor 10, it is merely necessary to rotate member 31 in a direction opposite from that employed when inserting the nozzle holder, until member 31 disengages threads 37. The nozzle holder is then in a position to, be grasped by the hand for its final movement outward. While either right-hand or'left hand threads'may be employed, it is convenient to employ right-hand threads, whereupon member 31 will be turned clockwise when inserting nozzle holder 17, and counterclockwise when removing the nozzle holder.

The form of the invention shown in FIGURE 4 isin many respects similar to the form of the invention shown in FIGURES 1 to 3. An outstanding difference is that the nozzle holder 17a projects outwardly from the outer periphery of the rotor so that, in this embodiment, the discharge through channel 25 of nozzle bushing 24 clears the outer periphery of rotor 10, making groove 44 unnecessary.

The virtue of making outer end 45 of nozzle holder 17 flush or substantially flush with the outer surface of rotor 10 is to reduce windage during rotation, and in consequence, the power required for driving the motor, and the virtue of extending nozzle holder 17a outwardly is that in such case the discharge through nozzle bushing 24 is outwardly from the rotor, making a groove 44, or its equivalent, unnecessary for reducing or avoiding erosion of the outer surface of the rotor by the discharge from the nozzle.

If desired, member 31 may be rotatably mounted, for example, on projection 26, e.g. by means of a screw 48, as illustrated in FIGURE 4.

Rotor 10, of course, may be of any design or construction other than that illustrated, whether conventional or otherwise. As illustrated, rotor 10 is provided with a conventional conduit 47 for the feed of liquid or fluidized solids, e.g. sludge, to an area adjacent the nozzle, the purposes of which being well understood in the art.

Having particularly described the invention, it is to be understood that this is by way of illustration and not of limitation, and that changes, omissions, additions, substitutions and/ or modifications maybe made without departing from the spirit thereof. It is therefore intended that the patent shall cover, by suitable expression in the claims, the various features of patentable novelty that reside in the invention.

I claim:

1. The combination with a centrifuge rotor having a separating chamber, a peripheral wall surrounding said chamber and an opening in said wall for the discharge of an efiiuent from said chamber, of a nozzle holder in said opening, said nozzle holder having an orienting projection extending laterally thereof and spaced from its ends, said opening having a lateral extension spaced outwardly from its inner end and extending outwardly to its outer end to'slidably accommodate said orienting projection, said lateral extension of said opening positioned in the direction of the axis of rotation between spaced planes at right angles to said axis and passing through the limits in the direction of said axis of said opening, a shoulder on the outer end of said orienting projection, a shoulder on the outer end of said nozzle holder positioned in spaced relation to said first-mentioned shoulder, a threaded member, said threaded member projecting in between said shoulders, said lateral extension of said opening having threads on its periphery complementary to the threads on said threaded member, means on said threaded member for engagement by a tool for turning said threaded member for engagement of the threads in said lateral extension of said opening to move said nozzle holder inwardly of said opening when said threaded member is turned in one direction and outwardly of said opening when said threaded member is turned in the opposite direction, a shoulder at the inner end of said lateral extension of said opening, and a shoulder on the inner end of said orienting projection for engagement of said shoulder at the inner end of said lateral extension of said opening to limit the inward movement of said nozzle holder in said opening.

2. The combination with a centrifuge rotor having a separating chamber, a peripheral Wall surrounding said chamber and an opening in said wall for the discharge of an efiiuent from the outer portion of said chamber, of a nozzle holder in said opening, said nozzle holder having an orienting projection extending laterally thereof and spaced from its ends, said opening having a lateral extension spaced outwardly from its inner end and extending outwardly to its outer end to slidably accommodate said orienting projection, a shoulder on the outer end of said orienting projection, a shoulder on the outer end of said nozzle holder positioned in spaced relation to said first-mentioned shoulder, a threaded member, said threaded member projecting in between said shoulders, said lateral extension of said opening having threads on its periphery complementary to the threads on said threaded member, means on said threaded member for engagement by a tool for turning said threaded member for engagement of the threads in said lateral extension of said opening to 5 move said nozzle holder inwardly of said opening when said threaded member is turned in one direction and outwardly of said opening when said threaded member is turned in the opposite direction, a shoulder at the inner end of the lateral extension of said opening, and a shoulderon the inner end of said orienting projection for engagement of said shoulder at the inner end of said lateral extension of said opening to limit the inward movement of said nozzle holder in said opening.

3. The combination with a centrifuge rotor having a separating chamber, a peripheral wall defining said chamber and an opening in said wall for the discharge of an efiiuent from the outer portion of said chamber, of a nozzle holder in said opening, said nozzle holder having an orienting projection extending laterally thereof, said opening having a lateral extension slidably accommodating said orienting projection, a rotatable threaded member, means holding said threaded member along a side of said holder and against movement longitudinally with respect to the axis of said nozzle holder, said lateral extension of said opening having threads on its periphery complementary to and engaging the threads on said threaded member, means on said threaded member for engagement by a tool for turning said threaded member for engagement of the threads in said lateral extension of said opening to move said nozzle holder inwardly when said threaded member is turned in the opposite direction and outwardly of said opening when said threaded member is turned in the opposite direction, and

means limiting the inward movement of said nozzle holder in said opening.

4. The combination with a centrifuge rotor having a separating chamber, a peripheral wall element defining said chamber and an opening in said wall element for the discharge of an efiiuent from the outer portion of said chamber, of a nozzle holder element in said opening, a threaded member disposed between said elements at one side of said nozzle holder element, means on one of said elements for holding said threaded member against movement in either direction along its own axis with respect to the said element, the other element having threads complementary to and engaging the threads on said threaded member, means on said threaded member for engagement by a tool to move said nozzle holder inwardly of said opening when said threaded member is turned in one direction and outwardly of said opening when said threaded member is turned in the opposition direction.

References Cited in the file of this patent UNITED STATES PATENTS 951,370 Hackett Mar. 8, 1910 2,509,711 Williams May 30, 1950 2,590,735 Svensjo Mar. 25, 1952 2,695,748 Millard Nov. 30, 1954 2,911,140 Johnson Nov. 3, 1959 2,958,461 P'eltzer Nov. 1, 1960 

4. THE COMBINATION WITH A CENTRIFUGE ROTOR HAVING A SEPARATING CHAMBER, A PERIPHERAL WALL ELEMENT DEFINING SAID CHAMBER AND AN OPENING IN SAID WALL ELEMENT FOR THE DISCHARGE OF AN EFFLUENT FROM THE OUTER PORTION OF SAID CHAMBER, OF A NOZZLE HOLDER ELEMENT IN SAID OPENING, A THREADED MEMBER DISPOSED BETWEEN SAID ELEMENTS AT ONE SIDE OF SAID NOZZLE HOLDER ELEMENT, MEANS ON ONE OF SAID ELEMENTS FOR HOLDING SAID THREADED MEMBER AGAINST MOVEMENT IN EITHER DIRECTION ALONG ITS OWN AXIS WITH RESPECT TO THE SAID ELEMENT, THE OTHER ELEMENT HAVING THREADS COMPLEMENTARY TO AND ENGAGING THE THREADS ON SAID THREADED MEMBER, MEANS ON SAID THREADED MEMBER FOR ENGAGEMENT BY A TOOL TO MOVE SAID NOZZLE HOLDER INWARDLY OF SAID OPENING WHEN SAID THREADED MEMBER IS TURNED IN ONE DIRECTION AND OUTWARDLY OF SAID OPENING WHEN SAID THREADED MEMBER IS TURNED IN THE OPPOSITION DIRECTION. 